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IS ADDITIONAL WATER A FRIEND OR AN ENEMY?
Master the key terms and head words.
achievement - достижение layer — слой
hydration - гидрация, присоеди- liquid — жидкость
specification — технические условия to cure — сохранять, исправлять»
124. Put down the corresponding verbs a) nouns b); translate the words.
Model: foundation - to found (a) to enrich - enrichment (b)
a) corrosion -to______ b) to enrich —__________ __^
hydration - to______ to require -____________
invention — to____ ____ to achieve —_____________
penetration -to________ to attach -______________
evaporation —to______ ____ to adjust —___________
relation — to_____
125. Read the combinations. Translate them from Russian.
covering material — материал покрытия
cover of roof — кровля
water/cement ratio — пропорция воды в растворе
concrete curing — выдержка бетона
compressive strength - сопротивление на сжатие
vapour pipe — паровой патрубок
vapour heating system — система парового отопления
126. a) Translate the given prepositions into English.
1. The cover zone is the layer (между)___ the steel reinforcement
and concrete surface.
2. The durability of cover zone depends (от)___ the mix design ctf
3. (В течение)_________ the period of concrete curing, a minimum
of cement content and a maximum of water/cement ratio is include^
4. Water is added (к)___ concrete (для)____ hydration of cement
5. Additional amounts of water increase the pores (в, внутри)__
the concrete's structure.
6. The process of concrete's curing lasts for (около)___ 28 days
b) Translate the examples into Russian. Mind Participle II.
1. ... additional amount of water poured into the mix...
2. ... required strength achieved with minimum cement content...
3. ... durability increased by adding water...
4. ... workability provided by the necessary amount of aggregates ...
Unit Eight. Concrete
Read and translate the article.
One of the key requirements of concrete service is its durability. And the quality of cover zone (покрытие) is of primary importance for providing concrete's durability. The cover zone is the concrete layer between the steel reinforcement and concrete surface. It should be taken into account that durability of concrete zone depends upon the mix design of concrete and the properties of the concrete itself.
The process of concrete's curing, as we know, lasts for about 28 days. And the compressive strength at 28 days is considered to be the basis of concrete specification. During the period of curing, engineers frequently include a minimum of cement (content) and a maximum of water/cement ratio into the mix.
Naturally, different construction purposes require different cement content, and for many types of mixes the required strength can be achieved with the minimum cement content. Engineers add water to concrete for hydration of cement. But the minimum amount of water needed for hydration of the mix may be too little to provide the necessary workability of the mix. So, in order to increase workability of concrete, additional amounts of water can be poured into the mix. And what is the result of this operation? It turns out that additional amounts of water increase the pores within the concrete's structure, especially after evaporation. It leads, in its turn, to an increase of gas, vapour, and liquid penetration into the structure of the mix. It is noted that especially strong this penetration is in the cover zone. So, one can see that additional water provides the potential for structural mix to decrease its durability. One more disadvantage of adding water to the concrete mix is its reinforcement corrosion and cracking. Additional corrosion and cracking provide new ways for gas, vapour, and liquids to penetrate into the cover zone. So, is additional water concrete's friend or enemy?
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